CVE-2023-52776 is a medium-severity vulnerability identified in the Linux kernel's ath12k wireless driver, which handles certain Qualcomm Atheros Wi-Fi chipsets. The vulnerability arises from improper synchronization in the handling of DFS (Dynamic Frequency Selection) radar and temperature events. Specifically, the active physical device contexts (pdevs) in ath12k are protected by Read-Copy-Update (RCU) mechanisms, but the DFS radar and temperature event handling code that calls ath12k_mac_get_ar_by_pdev_id() was not marked as a read-side critical section. This omission can lead to use-after-free conditions, where the code accesses memory that has been freed, potentially causing undefined behavior or integrity issues. Although the temperature event handler currently appears to be a placeholder, it still triggers RCU lock dependency warnings (lockdep splats), indicating a synchronization flaw. The fix involves marking the relevant code sections as RCU read-side critical sections to ensure proper synchronization and prevent use-after-free scenarios. The vulnerability has a CVSS v3.1 base score of 5.9, reflecting a medium severity level. It requires no privileges or user interaction to exploit but has a high attack complexity, and its impact is limited to integrity without affecting confidentiality or availability. No known exploits are reported in the wild at this time.

For European organizations, the vulnerability primarily threatens the integrity of systems running Linux kernels with the affected ath12k driver, which is common in devices using Qualcomm Atheros Wi-Fi chipsets. Potential impacts include corruption or manipulation of wireless driver state, which could lead to unstable wireless connectivity or subtle data integrity issues in network communications. While the vulnerability does not directly compromise confidentiality or availability, exploitation could be leveraged as part of a larger attack chain to undermine system reliability or facilitate privilege escalation. Organizations relying heavily on Linux-based infrastructure with wireless connectivity, such as enterprises, research institutions, and critical infrastructure operators, may face operational disruptions or increased risk of targeted attacks if the vulnerability is exploited. Given the medium severity and absence of known exploits, the immediate risk is moderate, but timely patching is advisable to prevent future exploitation, especially in sensitive environments.

1. Apply the official Linux kernel patches that mark the DFS radar and temperature event handling code as RCU read-side critical sections. Monitor Linux kernel updates and ensure affected systems are updated promptly. 2. Audit and inventory all devices running Linux kernels with Qualcomm Atheros ath12k drivers to identify exposure. 3. For devices where kernel updates are not immediately feasible, consider disabling DFS radar functionality temporarily if operationally acceptable, to reduce attack surface. 4. Implement network segmentation and strict access controls around wireless infrastructure to limit potential lateral movement if exploitation occurs. 5. Monitor system logs and kernel debug outputs for RCU lockdep warnings or anomalies that may indicate attempts to exploit this vulnerability. 6. Engage with hardware and software vendors to confirm support for patched drivers and coordinate update rollouts. 7. Incorporate this vulnerability into vulnerability management and incident response plans to ensure rapid detection and remediation.